中国科学院机构知识库网格系统: 检索

浏览/检索结果: 共5条，第1-5条

帮助

条数/页：排序方式：
	Propagation modes of 3D scour below a submarine pipeline in oblique steady currents and waves 会议论文 OAI收割 8th International Conference on Scour and Erosion, ICSE 2016, Oxford, United kingdom, September 12, 2016 - September 15, 2016 作者: Zang ZP(臧志鹏); Tang G; Cheng L 收藏 \| 浏览/下载：23/0 \| 提交时间：2017/05/05 Critical condition Embedment depth Incident angles Local scour Oblique incidence Propagation mode Shields parameters Steady current
	Fabrication of high-efficiency ultraviolet blazed gratings by use of direct Ar2-CHF3 ion-beam etching through a rectangular photoresist mask (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2011: Sensor and Micromachined Optical Device Technologies, May 24, 2011 - May 26, 2011, Beijing, China Tan X. 收藏 \| 浏览/下载：26/0 \| 提交时间：2013/03/25 In ultraviolet spectroscopy groove irregularity and surface roughness of nanometer magnitude can cause a significant loss of diffraction efficiency. Therefore there is a constant need to improve the diffraction efficiency. A blazed grating can concentrate most of the light intensity into a desired diffraction order it is important to control the groove shape precisely so it is the optimum choice among gratings of different kinds of profile. As the operating wavelength of most UV spectral applications is less than 200 nm especially the blaze angle and the apical angle. We have presented a direct shaping method to fabricate EUV blazed gratings by using an ion-beam mixture of Ar+ and CHF2 +to etch K9 glass with a rectangular photoresist mask. With this method the required blaze angle is small we have succeeded in fabricating well-shaped UV blazed gratings with a 1200 line/mm groove density and 8.54 blaze angles and 1200 line/mm groove density and 11.68 blaze angles and the metrical efficiency is about 81% and 78%. The good performance of the gratings was verified by diffraction efficiency measurements. When one uses the etching model the conditions on the ion-beam grazing incident angle and the CHF3partial pressure should be noted. Besides since the etched groove shape depends on the aspect ratio of the photoresist mask ridge if we wish to fabricate larger gratings with this method we must improve the uniformity of the photoresist mask before ion-beam etching. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
	Influence of spatial temperature distribution on high accuracy interferometric metrology (EI CONFERENCE) 会议论文 OAI收割 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China 作者: Yang H.; Zhang J.; Zhang J.; Zhang J.; Yan F. 收藏 \| 浏览/下载：29/0 \| 提交时间：2013/03/25 We calculate the influence of temperature change on the refractive index of air establish a model of air temperature distribution and analyze the effect of different temperature distribution on the high accuracy interferometric metrology. First a revised Edlen formula is employed to acquire the relation between temperature and refractive index of air followed by introducing the fixed temperature gradient distribution among the spatial grid within the optical cavity between the reference flat and the test flat of the Fizeau interferometer accompanied by a temperature change random function within each grid. Finally all the rays through the air layer with different incident angles are traced by Matlab program in order to obtain the final output position angle and OPD for each ray. The influence of different temperature distribution and the length of the optical cavity in on the testing accuracy can be analyzed through the RMS value that results from repeatable rays tracing. As a result the horizontal distribution (vertical to optical axis) has a large effect on the testing accuracy. Thus to realize the high accuracy figure metrology the horizontal distribution of temperature must be rigorously controlled as well as to shorten the length of the optical cavity to a large extent. The results from our simulation are of great significant for the accuracy analysis of interferometric testing and the research of manufacturing a interferometer. 2010 Copyright SPIE - The International Society for Optical Engineering.
	Transmission properties of multiband fss based on fractal elements (EI CONFERENCE) 会议论文 OAI收割 2010 9th International Symposium on Antennas Propagation and EM Theory, ISAPE 2010, November 29, 2010 - December 2, 2010, Guangzhou, China 作者: Gao J. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 Self-similar fractal elements that has multiband properties can be advantageously exploited to design simple multiband FSS on single screen. In this paper fractal Y aperture FSS has been designed using recursive technology and the periodic method of moments(PMoM) is employed to characterize the transmission properties of FSS as band-pass filters. The frequency response to the structure parameters when electromagnetic wave incident with different angles and polarizations is discussed and the numerical analysis show good correlation to the measured results. 2010 IEEE.
	目标反射特性对激光测距的影响期刊论文 OAI收割中国激光, 2008, 卷号: 35, 期号: 7, 页码: 1001, 1004 张雷洪; 杨艳; 臧华国; 胡善江; 陈卫标; 陆雨田收藏 \| 浏览/下载：2345/274 \| 提交时间：2009/09/18 激光技术激光测距双向反射分布函数朗伯体 Bidirectional reflection distribution function Incident angles Lambertian Laser rangefinder Laser technique